1. Field of Invention
The present invention relates to a pump and, more particularly, to an easily operable hand pump.
2. Related Prior Art
There have been many portable pumps on the market. Most of them include a telescopic structure consisting of two or three sections so as to occupy limited space in storage and to pump great volume of air in a stroke in use. A typical three-sectional structure includes a first cylinder, a second cylinder inserted in the first cylinder and a third cylinder inserted in the second cylinder. In operation, a user grips the first cylinder with one hand and the third cylinder with the other hand. The user pulls the first cylinder and the second cylinder from the third cylinder in order to draw air into the pump. The user pushes the first cylinder and the second cylinder toward the third cylinder in order to discharge air from the pump. The first cylinder is often thick enough for the user to grip adequately. However, the third cylinder is often too thin for the user to grip adequately.
The present invention is therefore intended to obviate or at least alleviate the problem encountered in the prior art.